Reproductive biology of Atropa belladonna: embryological features, pollen and seed viability.

An embryological study of the Bulgarian native populations of Atropa belladonna has been carried out. Some embryological features typical for the genus Atropa and the family Solanaceae were observed. A new feature, namely endosperm embryo, was also established. The recognised high plasticity of the female gametophyte, as well as the high pollen and embryo viability play an essential role for maintaining the size of populations of the studied species. The specific reproductive features observed are important for the use of A. belladonna as a source of raw material for the pharmaceutical industry and for its status as an endangered species in the Bulgarian flora.Peer Reviewe

On the gametogenesis and early embryogenesis in some olive tree cultivars

A comparative embryological study on two Spanish cultivars and one growing in Bulgaria of Olea europaea was carried out. The embryo sac develops according to Allium (bisporic)-type. The critical phases during the development of male and female gametophyte that lead to sterility and abortiveness of the embryo sacs and ovules are reported. The embryogenesis follows the Asterad-type. The endosperm passes a free nuclear stage and later on becomes cellular.Peer Reviewe